A plurality of signal anomalies are identified in a number of tubes in a steam generator. Since the geometry of the steam generator is known, the location of each signal anomaly along each tube is converted into a location within the interior of the steam generator. If a plurality of signal anomalies are at locations within the steam generator that are within a predetermined proximity of one another, such a spatial confluence of signal anomalies is determined to correspond with a loose part situated within the steam generator. Additional methodologies can be employed to confirm the existence of the loose part. Historic tube sheet transition signal data can be retrieved and subtracted from present signals in order to enable the system to ignore the relatively strong eddy current sensor signal of a tube sheet which would mask the relatively weak signal from a loose part at the tube sheet transition.

A drive device for an in-core neutron instrumentation system includes a safety circuit between a power supply and a drive motor. The safety circuit is provided inside the cover member, and switches between a conductive state in which power can be supplied to the drive motor and a cut-off state in which power cannot be supplied thereto depending on a mounted state of the cover member. The safety circuit is controlled to be in the conductive state in response to a state in which the cover member is mounted on the base member, and is controlled to be in the cut-off state in response to a state in which the cover member is not mounted on the base member.

A nozzle expansion tool includes a frame with a drive system on the frame. A rotary mandrel is drivingly connected to the drive system and is engageable with an expansion roller device. A plurality of vacuum cups are mounted to the frame and each include a vacuum fitting adapted to be connected to a vacuum source. A depth adjustment mechanism is connected to the expansion roller device and is configured to adjust a distance that the expansion roller device extends from the frame.

The nuclear power generation system of the present invention comprises a reactor vessel. It further comprises a first crane gantry defining a fuel rod path along which nuclear fuel rods can be moved to/from the reactor vessel and a second crane gantry defining a component path along which reactor vessel components can be moved to/from the reactor vessel. The the first and second crane gantries both have a fixed radial orientation relative to the reactor vessel.

A replacement thermal sleeve with a flange for a reactor vessel closure head penetration adapter housing. By altering a diameter of the flange, a replacement thermal sleeve can be installed through the narrow diameter of the penetration adapter housing opening from under the reactor vessel head. The flange can be compressible or expandable or the tubular wall of the thermal sleeve can be inserted in longitudinal sections, one at a time, into an opening in the underside of the penetration head adapter and reformed within the opening when fully inserted.

A bolt installation and removal (BIR) system is used for assembling and disassembling a nuclear vessel. The BIR system includes a platform with a stand for supporting the nuclear vessel. A track extends around an outside perimeter of the platform and multiple tool carts include wheels that roll on the track. Tool towers are located on the carts and include tool assemblies configured to install and remove bolts on the nuclear reactor vessel. Magazine towers also extend up from the tool carts next to the tool towers and include magazines that hold bolts for exchanging with the tool assemblies. Drive mechanisms move tool heads in the tool assemblies around a first vertical axis, vertically up and down, and laterally to more simply and reliably install and remove the bolts in a radioactive underwater environment.

A fuel assembly inspection system that utilizes a pressure transducer mounted to a utility's spent fuel handling tool to detect a relative change in depth of a fuel assembly during fuel inspections. The system then wirelessly transmits the signal to a fuel inspection recording system, which converts the signal to a relative height along the fuel assembly being viewed by a camera, and displays the relative height along with the applicable fuel assembly feature being viewed by the camera (e.g., nozzle, grid, span) via a text overlay on the video image of the inspection.

The method includes installing a system for inspecting the core shroud on the core shroud, driving the system horizontally around the core shroud, and using a sensor of the system to inspect the core shroud, where the system includes a trolley, an arm, a tether, and a remotely operated vehicle (ROV) for inspecting the core shroud. The ROV includes a body configured to be operatively connected to the tether, and the sensor is configured to be operatively connected to the body, and configured to provide inspection information of the core shroud. The arm is configured to be operatively connected to the trolley. The ROV is configured to be operatively connected to the arm via the tether, and the tether is configured to provide vertical position information for the ROV relative to the outer surface of the core shroud.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

A bolt repair platform includes a frame and a tool module. The tool module includes a tool having a first end configured to rotationally engage a bolt. The tool module also includes an actuator disposed between the tool and the frame so that actuation of the actuator moves the tool with respect to the frame. The frame is removably disposed on the structure, and the tool is movable with respect to the frame, so that, at each of a plurality of positions, the second end of the tool is capable of engagement with a respective bolt disposed in an internal support structure of a nuclear reactor vessel.